US Republican presidential candidates on Saturday praised a deal to release five Americans held in Iran, but said the Obama administration had conceded too much to win their freedom.
In a multi-pronged arrangement between two long-time enemies, the United States and Iran agreed on a prisoner swap on the same day their historic nuclear deal was fully implemented, which cleared the way for the lifting of sanctions on Tehran.
On the presidential campaign trail, New Jersey Governor Chris Christie accused President Barack Obama of being "an expert at making bad deals with the Iranians."
Florida Senator Marco Rubio said the United States should not be involved in prisoner deals because they only encourage the taking of more hostages.
Jeb Bush, the former Republican governor of Florida, called for new sanctions against Iran and cited an exclusive report from Reuters that the Obama administration refrained from imposing new sanctions last month after Tehran warned doing so could derail the prisoner deal.
Bush praised the Americans' release but added, "The bigger issue is that we've legitimised a regime that shows no interest in actually moving forward with the so-called community of nations."
Republican front-runner Donald Trump said at a campaign event that Iran would realise a windfall of $150 billion from the lifting of economic sanctions under the nuclear pact, which is meant to keep Iran from developing a nuclear weapon. That figure has been widely disputed and is thought to be closer to $100 billion.
Trump said he was happy Americans were being freed, "but I will tell you it's a disgrace that they were there for so long."
Meanwhile, House of Representatives Speaker Paul Ryan, a top Republican lawmaker, criticised the lifting of the sanctions, saying, "A bipartisan majority in the House voted to reject this deal in the first place, and we will continue to do everything possible to prevent a nuclear Iran."